Patterned epitaxial substrate and semiconductor structure

ABSTRACT

A patterned epitaxial substrate includes a substrate and a plurality of patterns. The substrate has a first zone and a second zone surrounding the first zone. The first zone is disposed around a center of the substrate. The patterns and the substrate are integrally formed, and the patterns are disposed on the substrate. The patterns include a plurality of first patterns and a plurality of second patterns. The first patterns are disposed in the first zone. The second patterns are disposed in the second zone. Sizes of the first patterns are different from sizes of the second patterns.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part application of and claims the priority benefit of U.S. application Ser. No. 16/669,526, filed on Oct. 31, 2019, now allowed, which claims the priority benefit of Taiwan application serial no. 108117777, filed on May 23, 2019. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND Technical Field

The disclosure relates to a substrate structure and a semiconductor structure; more particularly, the disclosure relates to a patterned epitaxial substrate and a semiconductor structure to which the patterned epitaxial substrate is applied.

Description of Related Art

With the advancement of photoelectric technologies, the volume of many photoelectric devices has gradually become smaller and smaller. In the process of manufacturing a micro light-emitting diode (LED), it is necessary to grow another different material (such as an epitaxial structure) on one material (such as an epitaxial substrate); in this case, the thermal expansion coefficient and the atomic lattice matching level of the two materials must be taken into consideration. The thermal temperature difference or the difference in the thermal expansion coefficient in a heating process and a lattice mismatch lead to uneven distribution of stresses, stress unevenness, thus causing warpage of the edge of the epitaxial substrate and resulting in a decrease in yield of subsequent manufacturing processes.

SUMMARY

The disclosure provides a patterned epitaxial substrate capable of preventing the warpage of the edge in the heating process and improving the yield of the subsequent manufacturing processes.

The disclosure further provides a semiconductor structure including the aforesaid patterned epitaxial substrate and featuring good photoelectric properties and reliability.

The disclosure further provides a semiconductor structure configured to adjust full band wavelength uniformity.

According to an embodiment of the disclosure, a patterned epitaxial substrate including a substrate and a plurality of patterns is provided. The substrate has a first zone and a second zone surrounding the first zone. The first zone is disposed around a center of the substrate. The patterns and the substrate are integrally formed, and the patterns are disposed on the substrate. The patterns include a plurality of first patterns and a plurality of second patterns. The first patterns are disposed in the first zone. The second patterns are disposed in the second zone. Sizes of the first patterns are different from sizes of the second patterns.

In an embodiment of the disclosure, each of the first patterns has a first orthogonal projection area on the substrate, each of the second patterns has a second orthogonal projection area on the substrate, and the first orthogonal projection area is greater than the second orthogonal projection area. Each of the first patterns has a first vertical height on the substrate, and each of the second patterns has a second vertical height on the substrate. Each of the first patterns has a first bottom width on the substrate, and each of the second patterns has a second bottom width on the substrate. The first vertical height is greater than the second vertical height, and the first bottom width is greater than the second bottom width.

In an embodiment of the disclosure, there is a first pitch between any two adjacent first patterns of the first patterns, there is a second pitch between any two adjacent second patterns of the second patterns, and the first pitch is less than the second pitch.

In an embodiment of the disclosure, a ratio of the first zone to the substrate is from 0.4 to 0.8. A ratio of the second zone to the substrate is 0.1 to 0.5.

In an embodiment of the disclosure, the substrate further has a third zone surrounding the second zone. The patterns further include third patterns. The third patterns are disposed in the third zone, and sizes of the third patterns are different from the sizes of the second patterns and the sizes of the first patterns. A ratio of the first zone to the substrate is from 0.4 to 0.8, and a ratio of the second zone to the substrate is from 0.1 to 0.5.

According to an embodiment of the disclosure, a semiconductor structure including a patterned epitaxial substrate, a first-type semiconductor layer, a light-emitting layer, and a second-type semiconductor layer is provided. The patterned epitaxial substrate includes a substrate and a plurality of patterns. The substrate has a first zone and a second zone surrounding the first zone, wherein the first zone is disposed around a center of the substrate. The patterns and the substrate are integrally formed, and the patterns are disposed on the substrate. The patterns include a plurality of first patterns and a plurality of second patterns. The first patterns are disposed in the first zone. The second patterns are disposed in the second zone. Sizes of the first patterns are different from sizes of the second patterns. The first-type semiconductor layer is disposed on the patterned epitaxial substrate. The light-emitting layer is disposed on the first-type semiconductor layer. The second-type semiconductor layer is disposed on the light-emitting layer.

According to an embodiment of the disclosure, a semiconductor structure including a first-type semiconductor layer, a plurality of patterns, a light-emitting layer, and a second-type semiconductor layer is provided. The first-type semiconductor layer has a top surface and a bottom surface opposite to each other. The bottom surface has a first zone and a second zone surrounding the first zone. The first zone is disposed around a center of the bottom surface. The patterns are disposed on the bottom surface of the first-type semiconductor layer, and the patterns and the first-type semiconductor layer are integrally formed. The patterns include a plurality of first patterns and a plurality of second patterns. The first patterns are disposed in the first zone. The second patterns are disposed in the second zone. Sizes of the first patterns are different from sizes of the second patterns. The light-emitting layer is disposed on the top surface of the first-type semiconductor layer. The second-type semiconductor layer is disposed on the light-emitting layer.

In an embodiment of the disclosure, the semiconductor structure further includes a wavelength converting layer with a particle size of less than 100 nanometers, disposed in the plurality of patterns.

In an embodiment of the disclosure, a volume ratio of the plurality of patterns to the wavelength converting layer is greater than or equal to 0.5 and less than or equal to 1.0.

In an embodiment of the disclosure, the plurality of patterns partially or completely pass through an area of the light-emitting layer.

In an embodiment of the disclosure, a minimum distance between the patterns passing through the area of the light-emitting layer is greater than or equal to 1 nanometer.

In an embodiment of the disclosure, a ratio of an etching depth of the plurality of patterns to a height of the semiconductor structure is less than or equal to 0.8.

In an embodiment of the disclosure, the first patterns of the first zone are random surround with different pitches.

In view of the above, according to the design of the patterned epitaxial substrate provided in one or more embodiments of the disclosure, the patterns and the substrate are integrally formed, the first zone and the second zone of the substrate are disposed in a concentric manner, and the sizes of the first patterns disposed in the first zone are different from the sizes of the second patterns in the second zone. Thereby, the issue of the warpage of the edge of the conventional substrate in the heating process can be effectively prevented, and the yield of the subsequent manufacturing processes can be improved. Besides, the semiconductor structure to which the aforesaid patterned epitaxial substrate is applied can have good photoelectric properties and reliability.

To make the above features and advantages provided in one or more of the embodiments of the disclosure more comprehensible, several embodiments accompanied with drawings are described in detail as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles described herein.

FIG. 1A is a schematic top view of a patterned epitaxial substrate according to an embodiment of the disclosure.

FIG. 1B is a schematic cross-sectional view of the patterned epitaxial substrate depicted in FIG. 1A along a line segment A-A′.

FIG. 2A is a schematic three-dimensional view of a portion of a patterned epitaxial substrate according to another embodiment of the disclosure.

FIG. 2B is a schematic three-dimensional view of a portion of a patterned epitaxial substrate according to still another embodiment of the disclosure.

FIG. 2C is a schematic cross-sectional view of a patterned epitaxial substrate according to still another embodiment of the disclosure.

FIG. 3A is a schematic top view of a patterned epitaxial substrate according to another embodiment of the disclosure.

FIG. 3B is a schematic cross-sectional view of the patterned epitaxial substrate depicted in FIG. 3A along a line segment B-B′.

FIG. 4 is a schematic top view of a patterned epitaxial substrate according to still another embodiment of the disclosure.

FIG. 5A is a schematic cross-sectional view of a semiconductor structure according to an embodiment of the disclosure.

FIG. 5B is a schematic cross-sectional view of a semiconductor structure according to another embodiment of the disclosure.

FIG. 6A is a schematic cross-sectional view of a semiconductor structure according to still another embodiment of the disclosure.

FIG. 6B is a schematic cross-sectional view of a semiconductor structure according to still another embodiment of the disclosure.

FIG. 7A is a schematic top view of a patterned epitaxial substrate according to an embodiment of the disclosure.

FIG. 7B is a schematic top view of a patterned epitaxial substrate according to another embodiment of the disclosure.

FIG. 7C is a schematic top view of a patterned epitaxial substrate according to another embodiment of the disclosure.

FIG. 8A is a schematic cross-sectional view of a semiconductor structure according to still another embodiment of the disclosure.

FIG. 8B is a schematic cross-sectional view of a semiconductor structure according to still another embodiment of the disclosure.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1A is a schematic top view of a patterned epitaxial substrate according to an embodiment of the disclosure. FIG. 1B is a schematic cross-sectional view of the patterned epitaxial substrate depicted in FIG. 1A along a line segment A-A′. With reference to FIG. 1A, a patterned epitaxial substrate 100 a provided in the embodiment includes a substrate 110 a and a plurality of patterns 120 a. The substrate 110 a has a center point C and has a first zone 112 a and a second zone 114 a surrounding the first zone 112 a. Specifically, the first zone 112 a and the second zone 114 a of the substrate 110 a are disposed in a concentric manner. In particular, the first zone 112 a and the second zone 114 a of the substrate 110 a, which should however not be construed as a limitation in the disclosure. Note that a ratio of the first zone 112 a to the substrate 110 a is from 0.4 to 0.8. If the ratio of the first zone 112 a to the substrate 110 a is less than 0.4 or greater than the 0.8, the problem of warpage of the edge cannot be well solved. Herein, the substrate 110 a is suitable for epitaxial growth, such as a sapphire substrate, a silicon wafer substrate, a carbide substrate, or a polymer substrate, which should however not be construed as a limitation in the disclosure.

According to the present embodiment, note that the substrate 110 a is divided into two zones (i.e., the first zone 112 a and the second zone 114 a) sharing the same center, and the first zone 112 a and the second zone 114 a respectively have the circular profile, which should however not be construed as limitations in the disclosure. In other embodiments that are not shown in the drawings, the substrate can also be divided into three or more zones sharing the same center, and the shape of each region can be a rectangular shape, a polygonal shape, or any other appropriate shape.

Besides, in this embodiment, the patterns 120 a provided and substrate 110 a are integrally formed, i.e., the patterns 120 a and the substrate 110 a are made of the same material and connected in a seamless manner. As shown in FIG. 1A, the patterns 120 a provided in the embodiment are arranged in an array on the substrate 110 a, and the patterns 120 a include a plurality of first patterns 122 a and a plurality of second patterns 124 a. The first patterns 122 a are disposed in the first zone 112 a, and the second patterns 124 a are disposed in the second zone 114 a. In an embodiment that is not shown in the drawings, the first patterns and the second patterns can also be arranged not in an array. Specifically, sizes of the first patterns 122 a are different from sizes of the second patterns 124 a.

In detail, each of the first patterns 122 a has a first orthogonal projection area on the substrate 110 a, and each of the second patterns 124 a has a second orthogonal projection area on the substrate 110 a. In the present embodiment, the first orthogonal projection area is greater than the second orthogonal projection area. That is, the sizes of the first patterns 122 a located in the first zone 112 a of the substrate 110 a are greater than the sizes of the second patterns 124 a located in the second zone 114 a.

With reference to FIG. 1B, as shown in the cross-sectional view, the cross-sectional shape of each of the patterns 120 a is a convex pattern, which should however not be construed as a limitation in the disclosure. In detail, each of the first patterns 122 a has a first vertical height H1 and a first bottom width W1, and there is a first pitch P1 between the adjacent first patterns 122 a. Each of the second patterns 124 a has a second vertical height H2 and a second bottom width W2, and there is a second pitch P2 between the adjacent second patterns 124 a. In the present embodiment, the first vertical height H1 is greater than the second vertical height H2, the first bottom width W1 is greater than the second bottom width W2, and the first pitch P1 is less than the second pitch P2. That is, the sizes of the first patterns 122 a located in the first zone 112 a of the substrate 110 a are greater than the sizes of the second patterns 124 a located in the second zone 114 a. Since the sizes of the second patterns 124 a are relatively small, stresses can be dispersed in the epitaxial growth process, so as to better solve the problem of warpage of the edge of the epitaxial substrate. Certainly, in other embodiments that are not shown in the drawings, the sizes of the first patterns located in the first zone of the substrate can also be smaller than the sizes of the second patterns located in the second zone according to actual demands, which still falls within the scope of protection in the disclosure. Note that the sizes include the orthogonal projection area, the vertical height, the bottom width, or the pitch between the adjacent patterns. As long as any of the orthogonal projection area, the vertical height, the bottom width, and the pitch is different, the sizes are deemed different.

Specifically, in an embodiment, a ratio of the height H and the bottom width W of the patterns 120 a is, for instance, from 0.2 to 0.9. If the ratio of the height H and the bottom width W of the patterns 120 a is greater than 0.9, defects are generated in an epitaxial structure (not shown) subsequently formed on the patterned epitaxial substrate 100 a. By contrast, if the ratio of the height H and the bottom width W of the patterns 120 a is less than 0.2, the light-emitting efficiency of the epitaxial structure subsequently formed on the patterned epitaxial substrate 100 a cannot be improved. In an embodiment, if the height H of the patterns 120 a is, for instance, greater than or equal to 10 nm and less than or equal to 1500 nm, the epitaxial structure subsequently formed on the patterned epitaxial substrate 100 a can have favorable light-emitting efficiency. In another embodiment, the bottom width W of the patterns 120 a is, for instance, greater than or equal to 0.1 μm and less than or equal to 2.5 μm, so that the epitaxial structure subsequently formed on the patterned epitaxial substrate 100 a can have favorable light-emitting efficiency. Besides, there is a pitch P between any two adjacent patterns 120 a, and the pitch P in an embodiment is less than or equal to 0.5 μm, which allows the epitaxial structure subsequently formed on the patterned epitaxial substrate 100 a to have favorable light-emitting efficiency.

In brief, according to the design of the patterned epitaxial substrate 100 a provided in the embodiment, the patterns 120 a and the substrate 110 a are integrally formed, and the first zone 112 a and the second zone 114 a of the substrate 110 a are disposed in a concentric manner. Specifically, the sizes of the first patterns 122 a disposed in the first zone 112 a of the substrate 110 a are different from the sizes of the second patterns 124 a located in the second zone 114 a. Thereby, the issue of the warpage of the edge of the conventional substrate in the heating process can be effectively prevented. That is, the yield of the subsequent manufacturing process can be improved through the design of the patterns 120 a of the patterned epitaxial substrate 100 a provided in the embodiment.

It should be mentioned that the structural type of the patterns 120 a is not construed as a limitation in the disclosure. In an embodiment, with reference to FIG. 2A, the patterns 120 b of the patterned epitaxial substrate 100 b are shaped as a cone on the substrate 110 a, and the corn shape allows the epitaxial structure subsequently formed on the patterned epitaxial substrate 100 a to have favorable light-emitting efficiency and light-emitting shapes. Alternatively, with reference to FIG. 2B, the patterns 120 c of the patterned epitaxial substrate 100 c are shaped as a cylinder on the substrate 110 a. Alternatively, with reference to FIG. 2C, the cross-sectional shape of the patterns 120 d of the patterned epitaxial substrate 100 d is a concave pattern; namely, the patterns 120 d sink in a direction from an upper surface 113 d to a lower surface 115 d of the substrate 110 d. Certainly, in other embodiments that are not shown in the drawings, the shape of the patterns can be selected from a polygonal cylinder, a polygonal cone, any other appropriate shape, or a combination thereof, which should however not be construed as a limitation in the disclosure.

It should be noted that the reference numerals and a part of the contents in the previous embodiment are used in the following embodiments, in which identical reference numerals indicate identical or similar components, and repeated description of the same technical contents is omitted. For a detailed description of the omitted parts, reference can be found in the previous embodiment, and no repeated description is contained in the following embodiments.

FIG. 3A is a schematic top view of a patterned epitaxial substrate according to another embodiment of the disclosure. FIG. 3B is a schematic cross-sectional view of the patterned epitaxial substrate depicted in FIG. 3A along a line segment B-B′. With reference to FIG. 1A and FIG. 3A, the patterned epitaxial substrate 100 e provided in the embodiment is similar to the aforesaid patterned epitaxial substrate 100 a, while the difference therebetween lies in that the patterned epitaxial substrate 100 e further has a third zone 116 e surrounding the second zone 114 e, and the third zone 116 e, the first zone 112 e, and the second zone 114 e are disposed in a concentric manner. Herein, the ratio of the first zone 112 e to the substrate 110 e is from 0.4 to 0.8, and the ratio of the second zone 114 e to the substrate 110 e is from 0.1 to 0.5, so as to better solve the problem of warpage of the edge. The patterns 120 e further include a plurality of third patterns 126 e, wherein the third patterns 126 e are disposed in the third zone 116 e of the substrate 110 e. Specifically, sizes of the third patterns 126 e are different from the sizes of the second patterns 124 e and the sizes of the first patterns 122 e.

In detail, each of the first patterns 122 e has a first orthogonal projection area on the substrate 110 e. Each of the second patterns 124 e has a second orthogonal projection area on the substrate 110 e. Each of the third patterns 126 e has a third orthogonal projection area on the substrate 110 e. The first orthogonal projection area, the second orthogonal projection area, and the third orthogonal projection area appear to be decreased in a progressive manner in a radial direction from each of the first patterns 122 e to each of the third patterns 126 e. That is, the orthogonal projection areas of the first patterns 122 e, the second patterns 124 e, and the third patterns 126 e sequentially on the first zone 112 e, the second zone 114 e, and the third zone 116 e of the substrate 110 e appear to have a progressive change and are gradually decreased.

To be more specific, the orthogonal projection area of the first patterns 122 e on the substrate 110 e is greater than the orthogonal projection area of the second patterns 124 e on the substrate 110 e, and the orthogonal projection area of the second patterns 124 e on the substrate 110 e is greater than the orthogonal projection area of the third patterns 126 e on the substrate 110 e. In other embodiments that are not shown in the drawings, the first orthogonal projection area, the second orthogonal projection area, and the third orthogonal projection area can also appear to be increased in a progressive manner, which should however not be construed as a limitation in the disclosure. In an embodiment, a rate of the progressive change is from 1% to 5%, for instance; that is, the proportion of the difference between the first orthogonal projection area and the third orthogonal projection area to the first orthogonal projection area is from 1% to 5%.

More particularly, with reference to FIG. 3B, in the cross-sectional view, each of the first patterns 122 e has a first vertical height H1 and a first bottom width W1, and there is a first pitch P1 between the adjacent first patterns 122 e. Each of the second patterns 124 e has a second vertical height H2 and a second bottom width W2, and there is a second pitch P2 between the adjacent second patterns 124 e. Each of the third patterns 126 e has a third vertical height H3 and a third bottom width W3, and there is a third pitch P3 between the adjacent third patterns 126 e. Specifically, in the radial direction from the first patterns 122 e to the third patterns 126 e, i.e., the first vertical height H1, the second vertical height H2, and the third vertical height H3 sequentially on the first zone 112 e, the second zone 114 e, and the third zone 116 e of the substrate 110 e appear to be decreased in a progressive manner, the first bottom width W1, the second bottom width W2, and the third bottom width W3 appear to be decreased in a progressive manner, and the first pitch P1, the second pitch P2, and the third pitch P3 appear to be increased in a progressive manner.

In detail, the first vertical height H1 is greater than the second vertical height H2, the second vertical height H2 is greater than the third vertical height H3, the first pitch P1 is less than the second pitch P2, and the second pitch P2 is less than the third pitch P3. In other embodiments that are not shown in the drawings, the first vertical height, the second vertical height, and the third vertical height can appear to be increased in a progressive manner, and the first pitch, the second pitch, and the third pitch can appear to be decreased in a progressive manner, which should however not be construed as limitations in the disclosure. In an embodiment, a rate of the progressive change is from 1% to 5%; that is, the proportion of the difference between the first vertical height H1 and the third vertical height H3 to the first vertical height H1 is from 1% to 5%, and the proportion of the difference between the first pitch P1 and the third pitch P3 to the first pitch P1 is from 1% to 5%.

In brief, according to the design of the patterned epitaxial substrate 100 e provided in the embodiment, the patterns 120 e and the substrate 110 e are integrally formed, and the first zone 112 e, the second zone 114 e, and the third zone 116 e of the substrate 110 e are disposed in a concentric manner. Specifically, the patterns 120 e appear to have a progressive change in a radial direction from the center to the edge of the substrate 110 e. Thereby, the issue of the warpage of the edge of the conventional substrate in the heating process can be effectively prevented. That is, the yield of the subsequent manufacturing process can be improved through the design of the patterns 120 e of the patterned epitaxial substrate 100 e provided in the embodiment.

FIG. 4 is a schematic top view of a patterned epitaxial substrate according to still another embodiment of the disclosure. With reference to FIG. 3A and FIG. 4, the patterned epitaxial substrate 100 f provided in the embodiment is similar to the aforesaid patterned epitaxial substrate 100 e, while the difference therebetween lies in that the first zone 112 f, the second zone 114 f, and the third zone 116 f of the substrate 110 f of the patterned epitaxial substrate 100 f provided in the embodiment share the same center C (are arranged in a concentric manner), wherein the first zone 112 f, the second zone 114 f, and the third zone 116 f are respectively shaped as a rectangle. The first orthogonal projection area, the second orthogonal projection area, and the third orthogonal projection area appear to be increased in a progressive manner in a radial direction from each of the first patterns 122 f to each of the third patterns 126 f. That is, the orthogonal projection areas of the first patterns 122 f, the second patterns 124 f, and the third patterns 126 f sequentially on the first zone 112 f, the second zone 114 f, and the third zone 116 f of the substrate 110 f appear to have a progressive change and are gradually increased.

To be more specific, the orthogonal projection area of the first patterns 122 f on the substrate 110 f is less than the orthogonal projection area of the second patterns 124 f on the substrate 110 f, and the orthogonal projection area of the second patterns 124 f on the substrate 110 f is less than the orthogonal projection area of the third patterns 126 f on the substrate 110 f. In other embodiments that are not shown in the drawings, the first orthogonal projection area, the second orthogonal projection area, and the third orthogonal projection area can also appear to be decreased in a progressive manner, which should however not be construed as a limitation in the disclosure.

In other embodiments that are not shown in the drawings, in the radial direction from the first patterns to the third patterns, note that the first vertical height, the second vertical height, and the third vertical height of the first patterns, the second patterns, and the third patterns can also appear to be decreased in a progressive manner; alternatively, the first pitch, the second pitch, and the third pitch of the first patterns, the second patterns, and the third patterns appear to be increased in a progressive manner, which still falls within the scope of protection provided herein.

FIG. 5A is a schematic cross-sectional view of a semiconductor structure according to an embodiment of the disclosure. With reference to FIG. 5A, the semiconductor structure 10 a provided in the present embodiment includes the patterned epitaxial substrate 100 a depicted in FIG. 1B, a first-type semiconductor layer 130, a light-emitting layer 140, and a second-type semiconductor layer 150. Specifically, the first-type semiconductor layer 130 is disposed on the patterned epitaxial substrate 100 a, the light-emitting layer 140 is disposed on the first-type semiconductor layer 130, and the second-type semiconductor layer 150 is disposed on the light-emitting layer 140. That is, the first-type semiconductor layer 130 and the second-type semiconductor layer 150 are respectively disposed on two sides of the light-emitting layer 140. Herein, the first-type semiconductor layer 130, the light-emitting layer 140, and the second-type semiconductor layer 150 can be defined as an epitaxial structure.

The patterned substrate 100 a depicted in FIG. 1B is applied in the semiconductor structure 10 a provided in the present embodiment, wherein the patterns 120 a and the substrate 110 a are integrally formed, and the first zone 112 a and the second zone 114 a of the substrate 110 a are disposed in a concentric manner. Specifically, the sizes of the first patterns 122 a disposed in the first zone 112 a of the substrate 110 a are different from the sizes of the second patterns 124 a located in the second zone 114 a. Thereby, the issue of the warpage of the edge of the conventional substrate in the heating process can be effectively prevented. In other words, the epitaxial structure to which the patterned epitaxial substrate 100 a depicted in FIG. 1B can have an improved manufacturing yield, so that the semiconductor structure 10 a can have good photoelectric properties and reliability. Note that the semiconductor structure 10 a provided in the present embodiment is, for instance, applied to a micro LED of which the height is less than or equal to 6 μm and the width is less than or equal to 100 μm. Since the sizes of the patterns 120 a in the nano-scale patterned epitaxial substrate 100 a are different, the semiconductor structure 10 a can have better photoelectric properties and reliability, which should however not be construed as a limitation in the disclosure.

FIG. 5B is a schematic cross-sectional view of a semiconductor structure according to another embodiment of the disclosure. With reference to FIG. 5B, the semiconductor structure 10 b provided in the present embodiment is similar to the aforesaid semiconductor structure 10 a, while the difference therebetween lies in that: in the present embodiment the semiconductor structure 10 b to which the patterned epitaxial substrate 100 e depicted in FIG. 3B is applied further has a third zone 116 e surrounding the second zone 114 e, and the third zone 116 e, the first zone 112 e, and the second zone 114 e are disposed in a concentric manner. The patterns 120 e further include a plurality of third patterns 126 e, wherein the third patterns 126 e are disposed in the third zone 116 e of the substrate 110 e. Specifically, sizes of the third patterns 126 e are different from the sizes of the second patterns 124 e and the sizes of the first patterns 122 e.

FIG. 6A is a schematic cross-sectional view of a semiconductor structure according to still another embodiment of the disclosure. With reference to FIG. 6A, the semiconductor structure 10 c provided in the present embodiment includes a first-type semiconductor layer 130′, a plurality of patterns 136, a light-emitting layer 140′, and a second-type semiconductor layer 150′. The first-type semiconductor layer 130′ has a top surface 132 and a bottom surface 134 opposite to each other, wherein the bottom surface 134 has a first zone 1302 and a second zone 1304 surrounding the first zone 1302, and the first zone 1302 and the second zone 1304 are disposed in a concentric manner. The patterns 136 and the first-type semiconductor layer 130′ are integrally formed and arranged in an array on the bottom surface 134 of the first-type semiconductor layer 130′. Herein, the patterns 136 provided in the embodiment are concave patterns; however, in other embodiments that are not shown in the drawings, the patterns can also be convex patterns or other appropriate patterns, which should however not be construed as a limitation in the disclosure. Particularly, the patterns 136 provided in the embodiment includes first patterns 1362 and second patterns 1364. The first patterns 1362 are disposed in the first zone 1302, and the second patterns 1364 are disposed in the second zone 1304. The sizes of the first patterns 1362 are different from the sizes of the second patterns 1364. The light-emitting layer 140′ is disposed on the top surface 132 of the first-type semiconductor layer 130′, and the second-type semiconductor layer 150′ is disposed on the light-emitting layer 140′.

In the semiconductor structure 10 c provided in the present embodiment, the patterns 136 and the first-type semiconductor layer 130′ are integrally formed, and the first zone 1302 and the second zone 1304 on the bottom surface 134 of the first-type semiconductor layer 130′ are arranged in a concentric manner. Particularly, the sizes of the first patterns 1362 located in the first zone 1302 are different from the sizes of the second patterns 1364 in the second zone 1304. Thereby, the full band wavelength uniformity of the light-emitting layer 140′ can be adjusted, so that the semiconductor structure 10 c can have better light-emitting efficiency.

FIG. 6B is a schematic cross-sectional view of a semiconductor structure according to still another embodiment of the disclosure. With reference to FIG. 6B, the semiconductor structure 10 d provided in the present embodiment is similar to the aforesaid semiconductor structure 10 c, while the difference therebetween lies in that the semiconductor structure 10 d provided in the present embodiment further has a third zone 1306 surrounding the second zone 1304, and the third zone 1306, the first zone 1302, and the second zone 1304 are disposed in a concentric manner. The patterns 136 further include a plurality of third patterns 1366 disposed in the third zone 1306 of the first-type semiconductor layer 130′. Specifically, the sizes of the third patterns 1366 are different from the sizes of the second patterns 1364 and the sizes of the first patterns 1362.

FIG. 7A is a schematic top view of a patterned epitaxial substrate according to an embodiment of the disclosure. With reference to FIG. 1A and FIG. 7A, the substrate 110 g provided in the embodiment is similar to the aforesaid substrate 110 a, while the difference therebetween lies in that the first patterns 122 a of the first zone 112 a are disposed around a center C of the substrate 110 a with the same pitch, and the first patterns 122 g of the first zone 112 g are random surround with different pitches. In more detail, the substrate 110 g has the first zone 112 g and the second zone 114 g surrounding the first zone 112 g. The patterns 120 g include a plurality of first patterns 122 g and a plurality of second patterns 124 g. The first zone 112 g is a randomly surrounded area, but surrounds the center C′ of the substrate 110 g. This means the first zone 112 g has no specific shape and the first patterns 122 g of the first zone 112 g are randomly arranged to more disperse the stress during epitaxy. The second patterns 124 g of the second zone 114 g are also randomly arranged, and the sizes of the first patterns 122 g located in the first zone 112 g of the substrate 110 g are greater than the sizes of the second patterns 124 g located in the second zone 114 g. In other words, the first zone can be surround completely (as shown in the first zone 112 a of FIG. 1A) or randomly (as shown in the first zone 112 g of FIG. 7A). Herein, a ratio of the first zone 112 g to the substrate 110 g is from 0.4 to 0.8, and a ratio of the second zone 114 g to the substrate 110 g is 0.1 to 0.5, so as to better solve the problem of warpage of the edge.

FIG. 7B is a schematic top view of a patterned epitaxial substrate according to another embodiment of the disclosure. With reference to FIG. 1A and FIG. 7B, the substrate 110 h provided in the embodiment is similar to the aforesaid substrate 110 a, while the difference therebetween lies in that the second zone 114 h of the substrate 110 h is randomly distributed outside the first zone 112 h. In more detail, the substrate 110 h has the first zone 112 h and the second zone 114 h surrounding the first zone 112 h. Herein, a part of the first zone 112 h and the second zone 114 h form a circle to surround another part of the first zone 112 h. In other words, the part of the first zone 112 h and the second zone 114 h are alternately arranged outside the another part of the first zones 112 h. The shapes of the part of the first zone 112 h and the second zone 114 h are both fan-like, and the shape of the another part of the first zone 112 h is circular. In addition, the patterns 120 h include a plurality of first patterns 122 h and a plurality of second patterns 124 h. The sizes of the first patterns 122 h located in the first zone 112 h of the substrate 110 h are greater than the sizes of the second patterns 124 h located in the second zone 114 h.

FIG. 7C is a schematic top view of a patterned epitaxial substrate according to another embodiment of the disclosure. With reference to FIG. 7A and FIG. 7C, the substrate 110 i provided in the embodiment is similar to the aforesaid substrate 110 g, while the difference therebetween lies in that the substrate 110 i further has a third zone 116 i, and the third zone 116 i and the second zone 114 i form a circle to surround the first zone 112 i. The second zone 114 i and the third zone 116 i are alternately arranged outside the first zones 112 i. In other words, the shapes of the second zone 114 i and the third zone 116 i are both fan-like, and the shape of the first zone 112 i is circular. Herein, a ratio of the first zone 112 i to the substrate 110 i is from 0.4 to 0.8, and a ratio of the second zone 114 i to the substrate 110 i is 0.1 to 0.5, so as to better solve the problem of warpage of the edge. In addition, the patterns 120 i include a plurality of first patterns 122 i, a plurality of second patterns 124 i and a plurality of third patterns 126 i. The sizes of the first patterns 122 i located in the first zone 112 i of the substrate 110 i are greater than the sizes of the second patterns 124 i located in the second zone 114 i and the sizes of the third patterns 126 i located in the third zone 116 i.

FIG. 8A is a schematic cross-sectional view of a semiconductor structure according to still another embodiment of the disclosure. With reference to FIG. 6A and FIG. 8A, the semiconductor structure 10 j provided in the present embodiment is similar to the aforesaid semiconductor structure 10 c, while the difference therebetween lies in that the semiconductor structure 10 j further includes a wavelength converting layer 160 j with a particle size of less than 100 nanometers, and the wavelength converting layer 160 j is disposed in the patterns CP. The wavelength converting layer 160 j includes a plurality of quantum dots 162 j, and the particle size of the quantum dots 162 j is less than 100 nanometers, preferably, is less than 30 nanometers, which can have better conversion rate.

In more detail, the semiconductor structure 10 j provided in the present embodiment includes a first-type semiconductor layer 130 j, a plurality of patterns CP, a light-emitting layer 140 j, and a second-type semiconductor layer 150 j. The patterns CP provided in the embodiment includes first patterns CP1 and second patterns CP2. The first patterns CP1 are disposed in the first zone 112 j of the substrate 110 j, and the second patterns CP2 are disposed in the second zone 114 j of the substrate 110 j. The sizes of the first patterns CP1 are different from the sizes of the second patterns CP2. The wavelength converting layer 160 j cover the first patterns CP1, the second patterns CP2 and part of the sidewall of the first-type semiconductor layer 130 j. Herein, a volume ratio of the patterns CP to the wavelength converting layer 160 j is greater than or equal to 0.5 and less than or equal to 1.0. In other words, there is a certain ratio between the volume of the grooves formed by the patterns CP and the filling volume formed by the wavelength converting layer 160 j. By adopting periodic patterned grooves (i.e. formed by the patterns CP) on the surface of the semiconductor structure 10 j, the wavelength converting layer 160 j can be easily filled in the patterns CP, thereby increasing the distribution density of quantum dots 162 j. The wavelength converting layer of the prior art is all configured only on the surface of the epitaxial structure which easily causes poor coverage of the surfaces or sidewalls. The present embodiment, the quantum dots 162 j are filled in the patterns CP which can effectively increase the absorption of blue light by the quantum dots 162 j, so as to improve the overall color conversion efficiency of the quantum dots 162 j.

FIG. 8B is a schematic cross-sectional view of a semiconductor structure according to still another embodiment of the disclosure. With reference to FIG. 8A and FIG. 8B, the semiconductor structure 10 k provided in the present embodiment is similar to the aforesaid semiconductor structure 10 j, while the difference therebetween lies in that the patterns CP′ partially or completely pass through an area of the light-emitting layer 140 k. In more detail, the patterns CP′ provided in the embodiment includes first patterns CP3 and second patterns CP4, and the sizes of the first patterns CP3 disposed in the first zone 112 k of the substrate 110 k are different from the sizes of the second patterns CP4 disposed in the second zone 114 k of the substrate 110 k. A port of the first patterns CP3 partially pass through the first-type semiconductor layer 130 k and extend into the area of the light-emitting layer 140 k. Another port of the first patterns CP3 completely pass through the first-type semiconductor layer 130 k and the area of the light-emitting layer 140 k, and extend into the second-type semiconductor layer 150 k. Therefore, when the wavelength converting layer 160 k is filled into the patterns C, the quantum dots 162 k can be closer to the light-emitting layer 140 k. In addition, the depth of the patterns CP can also be increased by etching to reduce the distance between the quantum dots 162 k and the light-emitting layer 140 k, thereby improving the color conversion efficiency. In particular, a minimum distance between the patterns CP passing through the area of the light-emitting layer is greater than or equal to 1 nanometer. If the minimum distance less than 1 nanometer, it is easy to cause defects in the light-emitting layer. In particular, a minimum distance between the patterns CP passing through the area of the light-emitting layer is between 1 nanometer to 100 nanometer to achieve a better color conversion efficiency. A ratio of an etching depth of the patterns to a height of the semiconductor structure is less than or equal to 0.8, preferably less than 0.5, to avoid chip damage and poor yield.

To sum up, according to the design of the patterned epitaxial substrate provided in one or more embodiments of the disclosure, the patterns and the substrate are integrally formed, different zones of the substrate are disposed in a concentric manner, and the sizes of the patterns disposed in different zones are different. Thereby, the issue of the warpage of the edge of the conventional substrate in the heating process can be effectively prevented, and the yield of the subsequent manufacturing processes can be improved. In an embodiment of the disclosure, the sizes (e.g., the orthogonal projection area, the vertical height, or the pitch) of the patterns in different zones can appear to have a progressive change (gradually increased or decreased) in a radial direction from the center to the edge of the substrate, so as to prevent warpage of the edge. Besides, the semiconductor structure to which the aforesaid patterned epitaxial substrate is applied can have good photoelectric properties and reliability.

It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure covers modifications and variations provided that they fall within the scope of the following claims and their equivalents. 

What is claimed is:
 1. A patterned epitaxial substrate comprising: a substrate having a first zone and a second zone surrounding the first zone, wherein the first zone is disposed around a center of the substrate; and a plurality of patterns disposed on the substrate, the plurality of patterns and the substrate being integrally formed, the plurality of patterns comprising: a plurality of first patterns disposed in the first zone; and a plurality of second patterns disposed in the second zone, wherein sizes of the plurality of first patterns are different from sizes of the plurality of second patterns.
 2. The patterned epitaxial substrate according to claim 1, wherein each of the plurality of first patterns has a first orthogonal projection area on the substrate, each of the plurality of second patterns has a second orthogonal projection area on the substrate, and the first orthogonal projection area is greater than the second orthogonal projection area, wherein each of the plurality of first patterns has a first vertical height on the substrate, each of the plurality of second patterns has a second vertical height on the substrate, each of the plurality of first patterns has a first bottom width on the substrate, each of the plurality of second patterns has a second bottom width on the substrate, the first vertical height is greater than the second vertical height, and the first bottom width is greater than the second bottom width.
 3. The patterned epitaxial substrate according to claim 1, wherein there is a first pitch between any two adjacent first patterns of the plurality of first patterns, there is a second pitch between any two adjacent second patterns of the plurality of second patterns, and the first pitch is less than the second pitch.
 4. The patterned epitaxial substrate according to claim 1, wherein a ratio of the first zone to the substrate is from 0.4 to 0.8, and a ratio of the second zone to the substrate is 0.1 to 0.5.
 5. The patterned epitaxial substrate according to claim 1, wherein the substrate further has a third zone surrounding the second zone, the plurality of patterns further comprise a plurality of third patterns disposed in the third zone, and sizes of the plurality of third patterns are different from the sizes of the plurality of second patterns and the sizes of the plurality of first patterns; wherein a ratio of the first zone to the substrate is 0.4 to 0.8, and a ratio of the second zone to the substrate is 0.1 to 0.5.
 6. A semiconductor structure comprising: a patterned epitaxial substrate comprising: a substrate having a first zone and a second zone surrounding the first zone, wherein the first zone is disposed around a center of the substrate; and a plurality of patterns disposed on the substrate, the plurality of patterns and the substrate being integrally formed, the plurality of patterns comprising: a plurality of first patterns disposed in the first zone; and a plurality of second patterns disposed in the second zone, wherein sizes of the plurality of first patterns are different from sizes of the plurality of second patterns; a first-type semiconductor layer disposed on the patterned epitaxial substrate; a light-emitting layer disposed on the first-type semiconductor layer; and a second-type semiconductor layer disposed on the light-emitting layer.
 7. A semiconductor structure comprising: a first-type semiconductor layer having a top surface and a bottom surface opposite to each other, the bottom surface having a first zone and a second zone surrounding the first zone, wherein the first zone is disposed around a center of the bottom surface; a plurality of patterns disposed on the bottom surface of the first-type semiconductor layer, the plurality of patterns and the first-type semiconductor layer being integrally formed, the plurality of patterns comprising: a plurality of first patterns disposed in the first zone; and a plurality of second patterns disposed in the second zone, wherein sizes of the plurality of first patterns are different from sizes of the plurality of second patterns; a light-emitting layer disposed on the top surface of the first-type semiconductor layer; and a second-type semiconductor layer disposed on the light-emitting layer.
 8. The semiconductor structure according to claim 7, further comprising: a wavelength converting layer with a particle size of less than 100 nanometers, disposed in the plurality of patterns.
 9. The semiconductor structure according to claim 8, wherein a volume ratio of the plurality of patterns to the wavelength converting layer is greater than or equal to 0.5 and less than or equal to 1.0.
 10. The semiconductor structure according to claim 7, wherein the plurality of patterns partially or completely pass through an area of the light-emitting layer.
 11. The semiconductor structure according to claim 10, wherein a minimum distance between the patterns passing through the area of the light-emitting layer is greater than or equal to 1 nanometer.
 12. The semiconductor structure according to claim 10, wherein a ratio of an etching depth of the plurality of patterns to a height of the semiconductor structure is less than or equal to 0.8.
 13. The semiconductor structure according to claim 7, wherein the first patterns of the first zone are random surround with different pitches. 